1. Field of the Invention
The present invention relates to attaching an airbag to the interior of a vehicle. More specifically, the present invention relates to an energy absorbing feature that may be used in conjunction with a mounting bracket to mount an inflatable curtain airbag to a vehicle.
2. Description of Related Art
Inflatable airbags are well accepted for use in motor vehicles and have been credited with preventing numerous deaths and injuries. In fact, the inclusion of inflatable safety restraint devices, or airbags, is now a legal requirement for many new vehicles. Airbags are typically installed throughout the passenger cabin of a vehicle, including the steering wheel. In the event of an accident, an accelerometer within the vehicle measures the abnormal deceleration and triggers the expulsion of rapidly expanding gases from an inflator. The expanding gases fill the airbags, which quickly inflate in front of the driver and passenger to protect them from impact against the windshield, dashboard, steering wheel, or other portions of the vehicle. Side impact airbags, such as curtain airbags, have also been developed in response to the need for protection from impacts in a lateral direction or against the side of the vehicle.
Recently, airbag technology has continued to advance such that curtain airbags are now enlisted to provide roll-over protection. (These airbags are sometimes referred to as “inflatable curtains.”) During a roll-over accident, the vehicle occupants can be jostled considerably, thereby causing the occupant to impact various parts of the vehicle interior. Even worse, the occupant may be ejected from the vehicle. Alternatively, a head or limb of an occupant may extend outside the vehicle during the roll-over. Such “occupant excursion” during roll-over accidents is a common cause of automotive fatalities, particularly in the case of vehicle occupants that are not wearing a seat belt during the roll-over.
Conventional curtain airbags attempt to combat the dangers of side impact or roll-over accidents by having a curtain airbag unroll or unfold downward from the roof of the vehicle and then inflate beside the person as a means of preventing the person from hitting the door, the window, or the side of the vehicle during lateral impact. Since a vehicle occupant may be leaning forward, reclined in the seat, or at any position in between, such airbags are typically long enough to cover the whole interior side of the vehicle, protecting occupants in both the front and rear occupant seats.
Generally, the curtain airbags must be sized to hold large volumes of inflation gas and descend below the window sill. Consequently, when not inflated the curtain airbag includes a significant amount of material. This material is then rolled, folded, or otherwise gathered to form a tight, tubular bundle. A sock that fits around the curtain may also be added to ensure that the curtain airbag is kept rolled or folded.
Generally, there are two types of mounting brackets that are used to mount inflatable curtains to the vehicle. The first type is sometimes referred to as a “conventional” bracket and is designed such that all (or substantially all) of the inflatable curtain, when mounted, will be positioned below the mounting bracket. A second type of mounting bracket is a “P-type” mounting bracket (which is sometimes called a “P-roll” bracket). In the P-type mounting bracket, the bracket is designed such that all (or substantially all) of the inflatable curtain, when mounted, will be positioned above the mounting bracket. (These brackets are called “P-type” because when the curtain is positioned above the bracket, the overall shape of the bracket and curtain resembles the shape of the letter “P”). An example of a P-type bracket that is known in the art is disclosed in a PCT patent publication that is published as International Publication No. WO 2005/049390. (This patent publication is referred to herein as the “390 application” and is expressly incorporated herein by reference.) Of course, other types of P-type mounting brackets are also known and used in the art.
The present paper is specifically devoted to addressing one or more of the problems associated with known P-type mounting brackets. As is known in the art, P-type brackets are designed such that during deployment of the inflatable curtain, the curtain rolls downward and over the bracket. This deployment must occur very quickly in order to protect the occupant during the crash. Accordingly, the gas entering the inflatable curtain during deployment will be highly pressurized and will cause the inflatable curtain to move/deploy very rapidly.
This rapid movement of the inflatable curtain during deployment places severe stress to the mounting bracket that is securing the inflatable curtain to the vehicle. In fact, in some situations, such rapid movement of the inflatable curtain has caused the P-type mounting bracket to fail, break, and/or separate from the vehicle structure. Obviously, such “failure” of the mounting bracket is undesirable. As such, manufactures often use multiple layers of fabric and/or reinforced fabric tabs in order to ensure that such “failure” of the mounting bracket does not occur.
Unfortunately, the use of these multiple and/or reinforced mounting brackets significantly raises the cost of the overall inflatable curtain airbag system. Accordingly, it would be an advancement in the art to provide a new system that uses P-type mounting brackets that is low cost and does not require the use of multiple and/or reinforced brackets to ensure proper functioning. Such a device is disclosed herein.